Dear TAG,
Some of you may be aware that an issue with the
xml:id specification began erupting the day
before it became a CR.
The issue has flowered nicely into a more general
discussion of what namespaces mean and what is
the W3C policy regarding their assignment in
recommendation track documents.
I've been asked to provide this information to you,
and as PureEdge AC rep I'd like to please request that
the TAG make a formal statement to all working groups
regarding these issues as soon as possible.
The kernel of the issue is my interpretation of
the definition of namespace as it appears in the
Namespaces recommendation. The definition is that
a namespace is a collection of names *identified*
by a URI. So, for example, the namespace
({lang, space}, http://www.w3.org/XML/1998/namespace)
is not equal to
({lang, space, base, id}, http://www.w3.org/XML/1998/namespace)
The W3C director directed the W3C to this interpretation in
http://www.w3.org/1999/10/nsuri, which states that a recommendation
cannot add more than clarifications and bug fixes without changing
the namespace URI.
Although I was unaware of this directive in particular,
I was familiar with what a namespace means according to
definition, and one aspect of C14N for XML 1.0 assumes
that further features would be added to a version of XML
whose namespace had changed.
More recently, we in the XForms working group were presented
with "W3C Policy choices" on namespaces for our next version,
in which keeping the same namespace was not an option. Although
it had become clear to me that there was therefore a policy, I
didn't know where the document was and didn't really look
(because it was in accord with my understanding).
XHTML 2 seems to be taking the same approach. Bjoern was nice
enough to send the link, though I will not speak for whether or
not he agrees with the policy.
Anyway, despite the director's directive, it is almost universally
not being followed in the past (e.g. xml:base, xslt, svg, etc.).
I seek direction from the TAG, or whomever is in authority to
make such a decision for the W3C, as to whether the
http://www.w3.org/1999/10/nsuri is repealed and recommendations
are encouraged to reuse namespaces or whether the W3C intends
to require correction of this problem going forward.
Thanks,
John Boyer, Ph.D.
Senior Product Architect and Research Scientist
PureEdge Solutions Inc.